Differential pressure gauge



March 1,1932. M. CONTE DIFFERENTIAL PRESSURE GAUGE Filed June 29. 1927 Patented Mar. 1, 1932 UNITED STATES PATENT OFFICE MAURICE CON TE, OF OU'GREE, NEAR LIEGE, BELGIUM, ASSIGNOR TO SOCIE'IE ANONYME DOUGREE-MARIHAYE, OE OUGREE, NEAR LIEGE, BELGIUM, A CORPORATION OF BELGIUM DIFFERENTIAL PRESSURE GAUGE Application filed June 29, 1927, Serial No. 202,324, and in Belgium July 14, 1926,

This invention relates to improvementsin or relating to differential pressure gauges andis particularly applicable to gas-meters.

A gauge constructed according to the pres- 5 ent invention dispenses with the annular float on the bell, and the flexible chain or the like to which the vertical rod, located in the central tube of the bell, is attached, is connected to a pulley which is fixed on the same axis as a cam. A thread is attached tothis cam and passes over the surface of same and has a counterweight suspended from its other extremity. The central tube has a rotatable plate, attachedto the base thereof, which plate is perforated exactly the-same as the base of said tube, hence, by rotating the plate, the area of the holes in the basecan be regulated. a

This apparatus is practically unaffected by variations of the surrounding temperature andthe oscillations in the pressures of the gas maybe damped. V

In order that the invention may be more readily understood reference may be made to the accompanying drawings in whichz.

, Figure 1 is a schematic section of a gauge constructed accordingltothe present inven tion.

Figures 2 and 3 are respectively a Vertical section and a plan of the central tube of the floatless bell.

A gauge constructed according to the present invention comprises a cylindrical container a in which a suitable-liquid b and the bell 0 dipping into the liquid 1), are enclosed. At the center ofthe base of the container a is located a mercury reservoir (Z, containing mercury 6 wherein the central tube f of the bell 0 is submerged. A rod 9 is secured in any convenient manner to the bottom of the tube f, which rod passes through an open tube 71,. of the container (1, one end of which is also submerged in said mercury, and which rod extends upwardly to the exterior of the container at. The two different pressures obtained in Venturi or Pitot tubes or a diaphragm, located within the main (not shown in the drawings) through which the gas flows, are transferred to the gauge through pipes i, 70 the high pressure pipe'i leading into the hell 0 and low pressure pipe is leading into the cylinder at. 7

A support Z, suitably located on the top of the cylinder a, carries the spindle m to which the pulley n and the cam 0 are secured. A

thread, chain, or the like p is attached to the upper end of the rod 9 and to the pulley n.

a In Figure 1 the apparatus is shown in the position it assumes when there is no gas fiowmg in the main. In this position the turning moment of the counterweight 8 about the center m is equal and opposite to the turning moment of theweight of the bell c and rod 9 about thecenter m. a

When gas flows in the main the bell 0 will rise since the pressure of the gas in the bell a will be greater than the pressure of the gas in'the cylinder a. The gradual increase in the difference between these two pressures will be balanced by the corresponding increase in the efiective weight of the bell as it rises out of the liquid b' in the cylinder at. This effective weight is also increased owing to the r0- tation of the pulley n and the cam 0 which decreases the turning moment of the counterweight 8.

The spindle m may carry a pointer or the like (not shown) which moves over a scale and the cam 0 maybe so designed that this scale may have constant dimensions or not as desired and in the latter case the scale may be as described in my above specification.

The apparatus for damping the oscillations in'the'pressures, which may be caused,

forinstance, by supplying the gas to the re- 7 ciprocating piston engines, consists of a plate u rotatably secured to the bottomt of the tube f.v The bottom of the tube 7 has a series of perforations and the plate M has an identical series ofperforations '0. One method of securing said plate a to the bottom t of the tubeconsists of screw-threading the lowor end of the rod g, passing same through t and u and screwing thereon the nut w. The relative position of the movable plate a in relation to the fixed part 6 permits the operative area of the perforations o to be adjusted, thus allowing the mercury e to pass more or less easily and hence forming an apparatus for damping the oscillations of the liquid levels within the gauge caused by the pressure oscillations or pulsations mentioned above.

Having now particularly described and ascertained the nature of this invention and-in What manner the same is to be performed, I declare that What I claim is:

1. A differential pressure gauge comprising a closed casing, a liquid partially fillingv said casing, a bell in said casing and dipping lnto said hquid, means for admitting two different pressures inside of the casing, one

pressure inside of the bell'and'the other pres-' sure outside of the bell, a rotatably mounted cam formed with a peripheral cam face having a radially" directed surface portion near the cam axis and curving from said portion gradually away from the axis to the outer end portion, a counterbalancing weight, flex-- ible means connected to the radiall'yvdirect'ed' portion of the peripheral face of said cam and lying on and extending over said peripheral cam face and connected to said counterbal ancing weight, said casing having an opening, and'a liquid-sealed motion transmitting} device combined with said bell and passing ,to the outside thereof and to the outside of said casing for transmitting the motion of said bell to said cam, the liquid seal of 'said' motion transmitting device serving to seal said opening, and said bell and counterbalancing means being so related through the mtermediary of said cam that said counterbalancing means will exert its maximum effort in opposition to the weight of the bell when the hell'occupies the position imposed" on it'by the minimum of differential pressure, whereby as said bell moves under the effect of increasing diflerential pressure and approaches the position'imposed on it by the maximum of difierential pressure, said counter-balancing means will approach its mini- "mum eii'ect.

ter-balancing means for said bell connected 2; A differential pressure gauge, comprising a closed casing, a liquid'partially filling said casing, a bell in said casing and dipping into the liquid, means for admitting a high pressure inside of the bell and a low pressure outside of the bell and inside of the casing,

to the cam face near the cam axis and extending over and engaging the cam face and depending therefrom, said bell and counterbalancing means being so related that said counterbalancing means will exert its maximum efiort in opposition to the weight of the bell when the bell occupies under the influence of the minimum differential pressure its most immersed position, whereby as the a bell rises due: to increase in the diiferencevincam, said casing having anopening, a liquid sealed motion transmitting-device combined with said belland'passingto: the outside of said casingfor'transmitting the motion of said belltosai'd' cam, the liquid seal'of said motion device serving toseal said opening,

and counterbalancing' means for said" bel sa-idbell and counterbalancmg means being so-related through'theintermediary of said" camthatsaid c'ounterbalancing 'means will exert its maximum efi'orfiin-opposition to the weight of the bell-"when t-he bell occupies the position imposed on it by the minimum of" diii'erential pressure, wherebyas said bell moves under the effect of increasing'difierem tial pressure and approaches the positionim posed on it by the maXimuInof'difi'erentiali pressure, said counterbalancing' means will approach its minimum of effort;

In testimony whereof,*. l have-signed my: name to this specification at- Brussels; Belgium, this 17th day 0f..Iun'e,1927i MAURICE CONTE;

arotatably mounted cam, said casing having an opening, a liquid-sealed motion transmit-' ting device combined'wit-hsaid bell andpassing to the outside of said casing for transmitting the'motion of said'bell to'said' cam,

the liquid seal of said motion transmitting de-:

vice serving to seal said opening,and' coun- 

